m40b16 into a 320i(m20b20)

[michael24m]

i'm going to do this swap for the better economy of city travel:D

i'm planning to put the m40b16 engine from a '89 316i into a '84 320i (le-jetronic).

what modification is needed for the electrical side of the story? i have the complete m40 engine, complete with electrics and all.
is this a relatively easy modification?
i also would want my diagnostics plug to work after the mod.
awaiting for your advice!
thanks!

[m-dtech]

you will need gearbox and prop too

electrics are easy

[michael24m]

i have the whole 316i donor car, so prop, no problem. i will also need the differential?

is this modification worth it?
what do you think?

[Morat]

why not upgrade to MS on your existing engine?

[m-dtech]

MS wont do much on a flat top IMO

if fuel economy is a problem then BMW is the wrong car for you.

[michael24m]

will i also need the differential fitted from the 316i for this mod?

[cliffybabe]

yep ur need th ediff aswell mate

[bmwe30mtech]

The M40 has a crap economy, it wont be much better, if any, than the 320i (amazingly). The M40 isnt great when it comes to mpg, noise etc. (im allowed to put it down, i have one).

Maybe you dont want a BMW, maybe a corsa....

[cliffybabe]

The M40 has a crap economy, it wont be much better, if any, than the 320i (amazingly). The M40 isnt great when it comes to mpg, noise etc. (im allowed to put it down, i have one).

Maybe you dont want a BMW, maybe a corsa....

yeah i can vouch for pauls statment i have seen him in action on the motorway, well did see him in action until we all left him

[bmwe30mtech]

The M40 has a crap economy, it wont be much better, if any, than the 320i (amazingly). The M40 isnt great when it comes to mpg, noise etc. (im allowed to put it down, i have one).

Maybe you dont want a BMW, maybe a corsa....

yeah i can vouch for pauls statment i have seen him in action on the motorway, well did see him in action until we all left him

You were well into the three figure speeds mate....m40 wont go much over the indicated 120. I need 2.5 power

[cliffybabe]

You were well into the three figure speeds mate....m40 wont go much over the indicated 120. I need 2.5 power

[liam012]

a 318is motor with 3.91 (or 3.73 if you are yhat fuel cautious) diff will yield great economy.

[michael24m]

wow, lots of feedback, thanks!

actually my m20b20 doesn't have such a high fuel consumption, but i was thinking the m40b16 has even better fuel economy and being motronic and all.

anyways, my m20b20 runs pretty smooth no problems.

so you are saying it's not worth the mod, even if mine is a LE-Jetronic engine?

[liam012]

what does your 2 litre give?
29mpg?
a 318is should give 36 maybe more

[michael24m]

well, i can't get my hands on an 318is engine
so if not, i'll sell the m40 lump, it's in good condition.

yes the 2 litre is making 23 mpg consumption wich i think it's pretty good for a 2.0 litre engine or not?:D

it's like 7.5-8.5 in litres per 100km




oh sorry i got the conversion all wrong...where i am from they do it litres per 100km


so it's like 34-35 mpg on the 2 litre sorry

[Brianmoooore]

i'm going to do this swap for the better economy of city travel

LPG your existing engine.

[320Touring]

i'm going to do this swap for the better economy of city travel

LPG your existing engine.

amen, or get a buspass, and use the car for fun stuff!

[michael24m]

yes, the LPG way.
let me guess if i get this right. it will have the same mpg, but with half the cost of the petrol? or will it have a slightly fewer mpg?
how about the power when running on LPG?
thanks!

[Brianmoooore]

LPG contains 20% less energy per litre than petrol (but the same by weight), so other things being equal, fuel consumption will rise 20%.
In practice you may get better than this, as the original fuel system may be past its best, and there is no excess fueling while the engine is warming up with LPG.
On the power side: A slight, but not noticeable, reduction in power if you use a single point venturi (cheap) system, or no reduction at all if you use a vapour injection (expensive) system.

[michael24m]

thank you for your advice!
i'm taking the LPG way into consideration. this seems like the best solution for my problem